Update the cusp/version.h to report 0.2.0.
Update the cusp/version.h to report 0.2.0.

It was previously reporting 0.1.0.  That's confusing since we've already
released 0.1.1.  Version 0.2.0 is just a tentative version number for
the next release.

vkirangoud/cusp-library,gshashidhar125/cusp-library,victordion/cusp-library,gshashidhar125/cusp-library,victordion/cusp-library,tectronics/cusp-library,baiyunping333/cusp-library,vkirangoud/cusp-library,vkirangoud/cusp-library,victordion/cusp-library,victordion/cusp-library,tectronics/cusp-library,gshashidhar125/cusp-library,baiyunping333/cusp-library,tectronics/cusp-library,baiyunping333/cusp-library,vkirangoud/cusp-library,baiyunping333/cusp-library,tectronics/cusp-library,gshashidhar125/cusp-library